dd0f34bc35
Co-authored-by: Todd Knight <T.Alan.Knight@gmail.com> Co-authored-by: Jeff Mitchell <jeffrey.mitchell@gmail.com> Co-authored-by: Michael Gaffney <mgaffney@users.noreply.github.com>
51 lines
1.1 KiB
Go
51 lines
1.1 KiB
Go
package schema
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import (
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"sort"
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)
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// statementProvider provides the migration statements in order.
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// Next should be called prior to calling Version() or ReadUp() or sentinel
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// values (-1 and nil) will be returned.
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type statementProvider struct {
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pos int
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versions []int
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up map[int][]byte
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}
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func newStatementProvider(dialect string, curVer int, opt ...Option) *statementProvider {
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const op = "schema.newStatementProvider"
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qp := statementProvider{pos: -1}
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qp.up = getUpMigration(dialect, opt...)
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for k := range qp.up {
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qp.versions = append(qp.versions, k)
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}
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sort.Ints(qp.versions)
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for len(qp.versions) > 0 && qp.versions[0] <= curVer {
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qp.versions = qp.versions[1:]
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}
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return &qp
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}
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func (q *statementProvider) Next() bool {
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q.pos++
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return len(q.versions) > q.pos
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}
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func (q *statementProvider) Version() int {
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if q.pos < 0 || q.pos >= len(q.versions) {
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return -1
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}
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return q.versions[q.pos]
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}
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// ReadUp reads the current up migration
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func (q *statementProvider) ReadUp() []byte {
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if q.pos < 0 || q.pos >= len(q.versions) {
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return nil
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}
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return q.up[q.versions[q.pos]]
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}
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